The present invention relates to a motor actuator.
A vehicle air conditioner of the prior art includes a blower duct switching door (various dampers) driven by a motor actuator that uses a motor as a drive source. Japanese Laid-Open Patent Publication No. 2004-304951 and Japanese Laid-Open Patent Publication No. 2012-90510 each describe an example of a motor actuator that accommodates an output mechanism, which includes a single motor and deceleration gears for decelerating and outputting the rotation of the motor, in a box-shaped housing. The housing includes a first case and a second case, which are overlapped with each other. A plurality of engagement pieces formed on an outer surface of the second case are snap-fitted and engaged with a plurality of engagement projections formed on an outer surface of the first case to fix the first case and the second case to each other. Further, the housing supports the motor. The housing supports a final stage of the deceleration gears that outputs the rotation of the motor to the exterior.
In addition to the single motor and the deceleration gears, the output mechanism of Japanese Laid-Open Patent Publication No. 2012-90510 further includes a position detection sensor, which outputs a position detection signal corresponding to a rotation position of the deceleration gear, a sensor signal line, which transmits the position detection signal output from the position detection sensor to a control unit that controls the rotation of the motor, and a power supplying terminal unit, which is connected to the motor to supply power to the motor. The sensor signal line and the power supplying terminal unit may be formed integrally with the position detection sensor so that the output mechanism may easily be coupled to the housing. In this structure, the sensor signal line, the power supplying terminal unit, and the position detection sensor are integrated with one another by, for example, an insulative resin material.
In recent years, left-right independently temperature-controlled type vehicle air conditioners and up-down independently temperature-controlled type vehicle air conditioners have increased to improve comfort in automobiles. Such a vehicle air conditioner allows for air conditioning to be finely controlled.
A left-right independently temperature-controlled type vehicle air conditioner and an up-down independently temperature-controlled type vehicle air conditioner include more blower duct switching doors than a left-right commonly temperature-controlled type vehicle air conditioner and an up-down commonly temperature-controlled type vehicle air conditioner. Accordingly, to drive the large number of blower duct switching doors, a left-right independently temperature-controlled type vehicle air conditioner and an up-down independently temperature-controlled type vehicle air conditioner includes a large number of actuators, such as those described in Japanese Laid-Open Patent Publication No. 2004-304951 and Japanese Laid-Open Patent Publication No. 2012-90510. However, a vehicle air conditioner that includes many actuators increases costs.
To reduce the number of components and the number of coupling steps, a single housing may accommodate a plurality of output mechanisms, each including a single motor and deceleration gears for decelerating and outputting the rotation of the motor. In other words, a single housing may accommodate a plurality of motors and deceleration gears for decelerating and outputting the rotation of the motors. This would reduce the number of components and the number of coupling steps.
However, the housing would be enlarged, and the central portion of the first case and the central portion of the second case would have a tendency of deforming. Further, a blower duct switching door is coupled directly or by a link mechanism to the one of the deceleration gears that outputs rotation. This applies load to such a gear. Further, a plurality of blower duct switching doors is coupled the actuator, which includes plural output mechanisms. This increases the load transmitted by the deceleration gear to the housing. In addition, the housing accommodates a plurality of motors, which are vibration generation sources. These factors may deform the housing.
Moreover, when a plurality of output mechanisms is simply accommodated in a single housing, a plurality of components forming the output mechanisms are coupled to a single housing. Thus, the motor actuator would be difficult to assemble.